Within the field of watch-making, a conventional architecture is used to make a movement, which may be provided with a striking mechanism, for example for minute repeaters. For an embodiment of this type, the gong used is a metal wire, for example made of steel, which may be of generally circular shape. This metal wire is arranged around the movement, in the watch frame. The gong is fixed, for example by soldering, to a gong-carrier, which is integral with the bottom plate of the watch. The gong vibration is generated by the impact, generally in proximity to the gong-carrier, of at least one hammer. The sound produced by the gong struck by the hammer is within the audible frequency range from 1 kHz to 20 kHz so as to indicate a well defined time, a programmed alarm time or a minute repeater to the person wearing the watch.
As mentioned above, in a mechanical or electro-mechanical watch, a striking mechanism may include one or more metal wire gongs, configured, for example, in a portion of a circle. Generally, the gong or gongs surround one part of the watch movement. Each gong may be struck by a respective hammer rotatably mounted on the bottom plate of the watch in proximity to the gong-carrier, and held by a spring element in an idle position as shown, for example in EP Patent No. 1 574 917.
In the state of the art, a hammer that is easily made of steel, particularly hardened steel, is always used. This hardened steel hammer is considered sufficiently hard to generate a sound when the hammer strikes the gong. However, with a hardened steel hammer, the acoustic level of the sound generated when the hammer strikes the gong is often not high enough and not crystalline for the watch user, which may be a drawback. Another drawback of the hardened steel hammer is that its volume density is not large enough. Consequently, there is insufficient inertial mass to produce a high acoustic level when the hammer strikes the gong.